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Apple Tree Diseases

September 19, 2015

 
QuestionWe moved to a new home about a year ago and it had an apple tree in the yard.

This spring it bloomed and small apples began to grow. After the apples were about walnut size I noticed a few brown spots on some of them. After about a week half the apple appeared rotten. Eventually all the apples did the same. I don't know what kind of apple tree this is, or how old it is. It's around 20 feet high. Do you know why this happened? Should I have sprayed it with something?

Answer Apples and pears tend to be more forgiving than peaches and plums when it comes to insect and disease issues, but if you want blemish free large fruits, you need to follow a spray schedule.  There are numerous diseases and insects which can attack.  Here is a link to our home fruit spray schedule:  http://www.uaex.uada.edu/publications/pdf/FSA-7503.pdf .  They also need to be pruned annually as well. 


 (April 2010)

QuestionI am having difficulty with my fruit trees.  Last year my peach tree produced lots of peaches, but they all dried up around the seed before they ripened. I also noticed that quite a few of the leaves and small branches dried up and died.   My apple tree made really good apples but the leaves dried up and died and I noticed yellow spots on the leaves that had several round dots in them. I assumed these to be some kind of insect eggs. The apples also had dark spots on them. I have already cut them back and am hoping that you can suggest some kind of spray, preferably something natural that I can use to solve these problems

 

AnswerFruit trees can be challenging for the home gardener, especially peaches which have numerous insect and disease issues.  Brown rot is the most destructive and can wipe out a crop seemingly overnight, especially when we have periods of rain, which were almost constant last year.  Pruning is something you will need to do annually, but a spray schedule is also necessary to produce quality fruit.  Purchase a home fruit spray which has both an insecticide and a fungicide mixed together.  There are organic products as well as non-organic. Start spraying when two thirds of the flower petals have fallen and then continue throughout the growing season, about every 10 days to three weeks depending on the weather.  Your apple tree sounds like it was infested with cedar apple rust.  This disease has two hosts--Eastern red cedars and apple trees.  By the time you see yellow spots rimmed in orange it is too late to spray to control it. The key is to do preventative sprays the first few weeks following bloom.  Orange gelatinous masses form on cedar trees releasing spores which then infest the apples.  Typically apple diseases are a bit easier to deal with since you can usually peel off the damage and still eat the fruit.  Spray schedules, cultural information and pruning guides are available on our Extension website at: http://www.arhomeandgarden.org/


(May 2010)

QuestionI live in northwest Arkansas and we have some small cedar trees at the edge of our lawn that has some orange (fungus?) looking things growing out of grey nuts? They look like a bunch of tentacles and are mushy. Are these harmful to the cedars?

 

AnswerWhat you are seeing with the bright orange tentacles is the fruiting body of cedar/apple rust on your cedar tree.  This disease has two hosts--Eastern Red Cedar and apples/crabapples.  The disease first starts on the cedar.  During periods of rain in the spring the galls quickly grow  orange, gelatinous tentacles that produce spores which then blow to the developing fruit and leaves on nearby apple and crabapples trees. Symptoms will appear on apple foliage as small round orange spots which then yellow.  Heavy infestations can cause the apple trees to shed foliage and deform the fruit lightly, but the disease is not deadly to either plant.  If you desire clean fruit, fruit sprays are needed in early spring.  They are only effective during the time the spores are active in early spring, and once you see symptoms, sprays are no longer effective.  If you don’t grow apple trees, you can ignore them or simply enjoy their odd appearance.  Here is a link to a fact sheet for more information: http://www.uaex.uada.edu/publications/PDF/FSA-7538.pdf


(June 2006)

QuestionWe planted a few young apple trees last year. They leafed out well, even had a few flowers and now small fruit--they have been growing great, but a few weeks ago I noticed some of the leaves looked black and wilty. I at first thought it was just because it was because they were still young but it doesn’t seem to be outgrowing it. Can you tell me what is wrong by this sample? What can I do to save the tree?

 

AnswerThe plant sample you sent has fireblight--a bacterial disease. Generally succulent, rapidly growing twigs and shoots are most susceptible. There is no sprayable cure, but the disease pressure should stop now that hot weather is here. This has been an extremely prolific fireblight year. Just cut out the damage 6-8 inches beneath where it is visible. Sterilize your pruning shears after each cut with rubbing alcohol or a Clorox solution. Be sure to clean and oil your shears when you are done pruning.


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